23.3.2. Configure Cross-Datacentre Replication (Library Mode)

Procedure 23.2. Configure Cross-Datacentre Replication (Library Mode)

1. Configure the Local Site

   1. Add the site element to the global element to add the local site (in this example, the local site is named LON).

      <infinispan>
         <global>
            ...
            <site local="LON" />
            ...   
         </global>
      </infinispan>
      

   2. Cross-site replication requires a non-default JGroups configuration. Add the transport element and set up the path to the configuration file as the configurationFile property. In this example, the JGroups configuration file is named jgroups-with-relay.xml.

      <infinispan>
         <global>
            ...
            <site local="LON" />
            <transport clusterName="default"> 
               <properties> 
                   <property name="configurationFile" value="jgroups-with-relay.xml" />     
                </properties> 
            </transport> 
            ...   
         </global>
      </infinispan>
      

2. Add the Contents of the Configuration File

   As a default, Red Hat JBoss Data Grid includes JGroups configuration files such as jgroups-tcp.xml and jgroups-udp.xml in the infinispan-core-{VERSION}.jar package.
   Copy the JGroups configuration to a new file (in this example, it is named jgroups-with-relay.xml) and add the provided configuration information to this file. Note that the relay.RELAY2 protocol configuration must be the last protocol in the configuration stack.

   <config> 
       ... 
       <relay.RELAY2 site="LON" 
                     config="relay.xml" 
                     can_become_site_master="true" 
                     max_site_masters="1"/> 
   </config>>
   

3. Configure the relay.xml File

   Set up the relay.RELAY2 configuration in the relay.xml file. This file describes the global cluster configuration.

   <RelayConfiguration> 
       <sites> 
           <site name="LON" 
                 id="0"> 
               <bridges> 
                   <bridge config="jgroups-global.xml" 
                           name="global"/> 
                   </bridges> 
           </site>  
           <site name="NYC" 
                 id="1"> 
               <bridges> 
                   <bridge config="jgroups-global.xml" 
                           name="global"/> 
                   </bridges> 
           </site>  
           <site name="SFO" 
                 id="2"> 
               <bridges> 
                   <bridge config="jgroups-global.xml" 
                           name="global"/> 
               </bridges> 
           </site> 
       </sites> 
   </RelayConfiguration>
   

4. Configure the Global Cluster

   The file jgroups-global.xml referenced in relay.xml contains another JGroups configuration which is used for the global cluster: communication between sites.
   The global cluster configuration is usually TCP-based and uses the TCPPING protocol (instead of PING or MPING) to discover members. Copy the contents of jgroups-tcp.xml into jgroups-global.xml and add the following configuration in order to configure TCPPING:

   <config> 
       <TCP bind_port="7800" ... /> 
       <TCPPING initial_hosts="lon.hostname[7800],nyc.hostname[7800],sfo.hostname[7800]"     
                num_initial_members="3" 
                ergonomics="false" /> 
             <!-- Rest of the protocols --> 
   </config>
   

   Replace the hostnames (or IP addresses) in TCPPING.initial_hosts with those used for your site masters. The ports (7800 in this example) must match the TCP.bind_port.

5. File Locations

   Ensure all the created files are on the classpath before using the new configurations.